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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,171 records · Page 65
All sourcesNASA NTRSDOE OSTI
DOE OSTI2012

Tritium Formation and Mitigation in High-Temperature Reactors

Tritium is a radiologically active isotope of hydrogen. It is formed in nuclear reactors by neutron absorption and ternary fission events and can subsequently escape into the environment. To prevent the tritium contamination of proposed reactor buildings and surrounding sites, this study examines the root causes and potential mitigation strategies for permeation of tritium (such as: materials selection, inert gas sparging, etc...). A model is presented that can be used to predict permeation rates of hydrogen through metallic alloys at temperatures from 450–750 degrees C. Results of the diffusion model are presented for a steady production of tritium

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2013

Tritium Formation and Mitigation in High-Temperature Reactor Systems

Tritium is a radiologically active isotope of hydrogen. It is formed in nuclear reactors by neutron absorption and ternary fission events and can subsequently escape into the environment. To prevent the tritium contamination of proposed reactor buildings and surrounding sites, this study examines the root causes and potential mitigation strategies for permeation of tritium (such as: materials selection, inert gas sparging, etc...). A model is presented that can be used to predict permeation rates of hydrogen through metallic alloys at temperatures from 450–750 degrees C. Results of the diffusion model are presented for a steady production of tritium

42 ENGINEERING↗
DOE OSTI2013

LANSCE Risk Mitigation (LRM) Risk Report for Module 2/FY14 Outage

The LANSCE Risk Mitigation Project (LRM) is a multi-year project being undertaken to increase the operating life-time of the accelerator (LINAC) portion of the LANSCE facility. The FY14 Outage is the first phase of LRM. Final planning for this outage is taking place during FY13. The main technical goal of the FY14 Outage is restoration of the 120 Hz macro-pulse repetition rate capability through the upgrade of the Module 2 portion of the 201 MHz drift tube LINAC (DTL) part of the facility.

42 ENGINEERING↗
DOE OSTI2013

Environmental Responses to Carbon Mitigation through Geological Storage

In summary, this DOE EPSCoR project is contributing to the study of carbon mitigation through geological storage. Both deep and shallow subsurface research needs are being addressed through research directed at improved understanding of environmental responses associated with large scale injection of CO 2 into geologic formations. The research plan has two interrelated research objectives. Objective 1: Determine the influence of CO 2 -related injection of fluids on pore structure, material properties, and microbial activity in rock cores from potential geological carbon sequestration sites. Objective 2: Determine the Effects of CO 2 leakage on shallow subsurface ecosystems (microbial and plant) using field experiments from an outdoor field testing facility.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2014

Light Water Reactor Sustainability Program: BWR High-Fluence Material Project: Assessment of the Role of High-Fluence on the Efficiency of HWC Mitigation on SCC Crack Growth Rates

As nuclear power plants age, the increasing neutron fluence experienced by stainless steels components affects the materials resistance to stress corrosion cracking and fracture toughness. The purpose of this report is to identify any new issues that are expected to rise as boiling water reactor power plants reach the end of their initial life and to propose a path forward to study such issues. It has been identified that the efficiency of hydrogen water chemistry mitigation technology may decrease as fluence increases for high-stress intensity factors. This report summarizes the data available to support this hypothesis and describes a program plan to determine the efficiency of hydrogen water chemistry as a function of the stress intensity factor applied and fluence. This program plan includes acquisition of irradiated materials, generation of material via irradiation in a test reactor, and description of the test plan. This plan offers three approaches, each with an estimated timetable and budget.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Assessment of Threats to Wetland Integrity at New Boston Air Force Station, New Hampshire, with Recommendations for Mitigation

Our study addressed two projects identified in the Integrated Natural Resources Management Plan (INRMP) for New Boston Air Force Station (NBAFS), New Hampshire that are related to sustaining high-quality wetland habitats on the station. These studies were intended to: (1) evaluate erosion and its impacts on NBAFS wetlands, (2) evaluate degraded wetlands for restoration potential and (3) develop designs for wetland restoration. This report includes brief descriptions of each wetland evaluated, existing and potential erosion problems at each wetland, and recommendations for restoration actions to mitigate impacting factors at high risk wetlands. In October 2011, we surveyed 15 wetlands on NBAFS for evidence of impacts from erosion. These wetlands were chosen because they were adjacent to roads, developed areas, or disturbed areas, and therefore had a higher potential for impact from erosion. Parameters evaluated at these wetlands and adjacent areas included (1) evidence of existing sedimentation and erosion into wetland areas; (2) source of sediment; (3) slope; (4) soil type; (5) surrounding land cover; (6) presence and extent of intervening non-erosive land (e.g., vegetated surface, pavement); (7) water inputs (surface runoff, groundwater); and (8) frequency and nature of erosion events. The evaluation was watershed-based and utilized existing topographic information to determine the watershed of each wetland. Erosion problems at specific locations were ranked according to risk, including probability of occurrence, magnitude of effect, and severity of effects. Our evaluations were used to determine opportunities for wetland restoration. Restoration activities were developed on a case-by-case basis with an emphasis on wetlands at highest risk of degradation. Our recommendations for restoration focused on eliminating or reducing risk using minimally intrusive procedures and engineering solutions that could be achieved at relatively low cost. We emphasize concepts such as permeable paving, stabilization of road surfaces, nonnative plant removals, and native plant buffers that eliminate the source of the disturbance or reduce the energy of runoff while increasing groundwater infiltration rates. Recommended restoration actions and solutions are intended to be sufficiently explicit to develop work plans for restoration activities.

Van Lonkhuyzen, Robert A.↗
DOE OSTI2012

ORNL Parking Structure Mitigation Report

Approximately 200 feet of an unnamed tributary to Fifth Creek and approximately 0.08 acres of wetland were impacted as a result of the construction of a new parking structure at Oak Ridge National Laboratory (ORNL) that was completed in Fiscal Year 2011. Compensatory mitigation, as per requirements set by the Tennessee Department of Environment and Conservation (TDEC), included the following: • On-site expansion of an existing wetland (P2) by 0.04 acres adjacent to the new ORNL parking structure. • On-site enhancement and preservation of approximately 800 feet of First Creek (between White Oak Avenue and West End Circle), 400 feet of White Oak Creek (at Building 4515, the High Temperature Materials Laboratory), and associated riparian zones.

Giffen, Neil R.↗
DOE OSTI2014

Formaldehyde and acetaldehyde exposure mitigation in US residences: In-home measurements of ventilation control and source control

Measurements were taken in new US residences to assess the extent to which ventilation and source control can mitigate formaldehyde exposure. Increasing ventilation consistently lowered indoor formaldehyde concentrations. However, at a reference air exchange rate of 0.35 h -1 , increasing ventilation was up to 60% less effective than would be predicted if the emission rate were constant. This is consistent with formaldehyde emission rates decreasing as air concentrations increase, as observed in chamber studies. In contrast, measurements suggest acetaldehyde emission was independent of ventilation rate. To evaluate the effectiveness of source control, formaldehyde concentrations were measured in Leadership in Energy and Environmental Design (LEED) certified/Indoor airPLUS homes constructed with materials certified to have low emission rates of volatile organic compounds (VOC). At a reference air exchange rate of 0.35 h -1 , and adjusting for home age, temperature and relative humidity, formaldehyde concentrations in homes built with low-VOC materials were 42% lower on average than in reference new homes with conventional building materials. Without adjustment, concentrations were 27% lower in the low-VOC homes. The mean and standard deviation of formaldehyde concentration were 33 μg m-3 and 22 μg m -3 for low-VOC homes and 45 μg m -3 and 30 μg m -3 for conventional.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2012

Common-Cause Failure Mitigation Practices and Knowledge Gaps

This technical report documents the findings from first phase of research activities by ORNL. Specifically, the report describes the results of the investigation of CCF mitigation practices and determination of knowledge gaps.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2015

Investigation of dynamics of ELM crashes and their mitigation techniques

The accurate prediction of H-mode pedestal dynamics is critical for planning experiments in existing tokamaks and in the design of future tokamaks such as ITER and DEMO. The main objective of the proposed research is to advance the understanding of the physics of H-mode pedestal. Through advances in coupled kinetic-MHD simulations, a new model for H-mode pedestal and ELM crashes as well as an improved model for the bootstrap current will be developed. ELMmitigation techniques will also be investigated. The proposed research will help design efficient confinement scenarios and reduce transient heat loads on the divertor and plasma facing components. During the last two years, the principal investigator (PI) of this proposal actively participated in physics studies related to the DOE Joint Research Targets. These studies include the modeling of divertor heat load in the DIII-D, Alcator C-Mod, and NSTX tokamaks in 2010, and the modeling of H-mode pedestal structure in the DIII-D tokamak in 2011. It is proposed that this close collaboration with experimentalists from major US tokamaks continue during the next funding period. Verification and validation will be a strong component of the proposed research. During the course of the project, advances will be made in the following areas; Dynamics of the H-mode pedestal buildup and recovery after ELM crashes – The effects of neutral fueling, particle and thermal pinches will be explored; Dynamics of ELM crashes in realistic tokamak geometries – Heat loads associated with ELM crashes will be validated against experimental measurements. An improved model for ELM crashes will be developed; ELM mitigation – The effect of resonant magnetic perturbations on ELMs stability and their evolution will be investigated; Development of a new bootstrap current model – A reduced model for will be developed through careful verification of existing models for bootstrap current against first-principle kinetic neoclassical simulations. The primary focus here will be on plasma regimes where the existing reduced models deviate from each other, such as high-beta and low aspect ratio plasmas; and Results will be verified against analytical models and simulation results from other codes. Simulation results will be compared with diagnostic experimental data such as Thomson measurements (HRTC) or flux measurements if available. We have arrangements with experimentalists from DIII-D and JET to use diagnostic edge data for this validation. In summary, we propose to study the H-mode pedestal buildup, the stability and evolution of ELMs using a model that will account for dynamically evolving neoclassical sources.

42 ENGINEERING↗
DOE OSTI2015

A wedge-based approach to estimating health co-benefits of climate change mitigation activities in the United States

While it has been recognized that actions reducing greenhouse gas (GHG) emissions can have significant positive and negative impacts on human health through reductions in ambient fine particulate matter (PM2.5) concentrations, these impacts are rarely taken into account when analyzing specific policies. This study presents a new framework for estimating the change in health outcomes resulting from implementation of specific carbon dioxide (CO 2 ) reduction activities, allowing comparison of different sectors and options for climate mitigation activities. Our estimates suggest that in the year 2020, the reductions in adverse health outcomes from lessened exposure to PM2.5 would yield economic benefits in the range of $6 to $14 billion (in 2008 USD), depending on the specific activity. This equates to between $40 and $93 per metric ton of CO 2 in health benefits. Specific climate interventions will vary in the health co-benefits they provide as well as in potential harms that may result from their implementation. Rigorous assessment of these health impacts is essential for guiding policy decisions as efforts to reduce GHG emissions increase in scope and intensity.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2015

Turbine Aeration Design Software for Mitigating Adverse Environmental Impacts Resulting From Conventional Hydropower Turbines

Conventional hydropower turbine aeration test-bed for computational routines and software tools for improving environmental mitigation technologies for conventional hydropower systems. In achieving this goal, we have partnered with Alstom, a global leader in energy technology development and United States power generation, with additional funding from the Initiative for Renewable Energy and the Environment (IREE) and the College of Science and Engineering (CSE) at the UMN

13 HYDRO ENERGY↗
DOE OSTI2016

Game Theory for Proactive Dynamic Defense and Attack Mitigation in Cyber-Physical Systems

While there has been a great deal of security research focused on preventing attacks, there has been less work on how one should balance security and resilience investments. In this work we developed and evaluated models that captured both explicit defenses and other mitigations that reduce the impact of attacks. We examined these issues both in more broadly applicable general Stackelberg models and in more specific network and power grid settings. Finally, we compared these solutions to existing work in terms of both solution quality and computational overhead.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2016

Mitigating Interconnection Challenges of the High Penetration Utility-Interconnected Photovoltaic (PV) in the Electrical Distribution Systems: Cooperative Research and Development Final Report, CRADA Number CRD-14-563

Various interconnection challenges exist when connecting distributed PV into the electrical distribution grid in terms of safety, reliability, and stability of the electric power systems. Some of the urgent areas for research, as identified by inverter manufacturers, installers and utilities, are potential for transient overvoltage from PV inverters, multi-inverter anti-islanding, impact of smart inverters on volt-VAR support, impact of bidirectional power flow, and potential for distributed generation curtailment solutions to mitigate grid stability challenges. Under this project, NREL worked with SolarCity to address these challenges through research, testing and analysis at the Energy System Integration Facility (ESIF). Inverters from different manufacturers were tested at ESIF and NREL's unique power hardware-in-the-loop (PHIL) capability was utilized to evaluate various system-level impacts. Through the modeling, simulation, and testing, this project eliminated critical barriers on high PV penetration and directly supported the Department of Energy's SunShot goal of increasing the solar PV on the electrical grid.

14 SOLAR ENERGY↗
DOE OSTI2016

Ultrasonic Foam Mitigation in Residual Oil Conversion Process: CRADA Final Report

Los Alamos National Laboratory (LANL) and the CRADA partner will be investigating the use of LANL’s advanced acoustic technology in applications related to foam mitigation in residual oil conversion process. This is important from the perspective of improving light hydrocarbons yields, and hence to, national energy security.

02 PETROLEUM↗